package com.yujie.utils;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class VerifyCodeUtil {
     public void createVerifyCode(HttpServletRequest request, HttpServletResponse response){
         try {

             int width=200;

             int height=69;

             BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);

             //生成对应宽高的初始图片

             String randomText = VerifyCode.drawRandomText(width,height,verifyImg);
             //把验证码存储在域对象
             request.getSession().setAttribute("code",randomText);

             response.setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别

             OutputStream os = response.getOutputStream(); //获取文件输出流

             ImageIO.write(verifyImg,"png",os);//输出图片流

             os.flush();

             os.close();//关闭流

         } catch ( IOException e) {
             //this.logger.error(e.getMessage());

             e.printStackTrace();
         }
     }
}
class VerifyCode {
    public static  String drawRandomText(int width, int height, BufferedImage verifyImg) {

        Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();

        graphics.setColor(Color.WHITE);//设置画笔颜色-验证码背景色

        graphics.fillRect(0, 0, width, height);//填充背景

        graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));

        //数字和字母的组合

        String baseNumLetter=  "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";

        StringBuffer sBuffer = new StringBuffer();

        int x = 10;  //旋转原点的 x 坐标

        String ch = "";

        Random random = new Random();

        for(int i = 0;i < 4;i++){

            graphics.setColor(getRandomColor());

            //设置字体旋转角度

            int degree = random.nextInt() % 30;  //角度小于30度

            int dot = random.nextInt(baseNumLetter.length());

            ch = baseNumLetter.charAt(dot) + "";

            sBuffer.append(ch);

            //正向旋转

            graphics.rotate(degree * Math.PI / 180, x, 45);

            graphics.drawString(ch, x, 45);

            //反向旋转

            graphics.rotate(-degree * Math.PI / 180, x, 45);

            x += 48;

        }

        //画干扰线

        for (int i = 0; i <6; i++) {

            // 设置随机颜色

            graphics.setColor(getRandomColor());

            // 随机画线

            graphics.drawLine(random.nextInt(width), random.nextInt(height),

                    random.nextInt(width), random.nextInt(height));

        }

        //添加噪点

        for(int i=0;i<30;i++){

            int x1 = random.nextInt(width);

            int y1 = random.nextInt(height);

            graphics.setColor(getRandomColor());

            graphics.fillRect(x1, y1, 2,2);

        }

        return sBuffer.toString();

    }

    /**
     * 随机取色
     */

    private static Color getRandomColor() {

        Random ran = new Random();

        Color color = new Color(ran.nextInt(256),

                ran.nextInt(256), ran.nextInt(256));

        return color;

    }
}
